Cannot Bind to specific network interface

I'm in the situation where using Funkload to test some web pages I need to specify which local network interface to use and it seems it is impossible with the current code...

I've already looked around, because I needed it badly, and found a way to do it by patching some of the files here, mainly: FunkLoadTestCase.py and PatchWebunit.py.

In case there's any interest for it I could commit the changes here as well ... just tell me how to proceed.